Learning Foreign Language Technique
This is a useful training video I guess. It does do a bit more oversimplifying. It's pretty logical that the "putting yourself out there" and actually using your Japanese etc. but it's obviously a technique that is more suited to confident extroverts. So it is also (I'd say quite strongly) a matter of personality.
To me walking up to a strange couple on the beach with a kid is a bit creepy. Could you imagine the reaction to some strange Japanese guy wandering onto Bondi and doing the same in English? It's not just a matter of your personality, but there's as well. I personally feel worse about that kind of situation, if you are just talking/being friendly to practice your Japanese, it feels like a bit of an abuse of the relationship there.
I did like this video though. It also manages to be amusing. When the couple are talking about his shoes, it sounds and looks like they are talking about the size of a certain male body part.